I've cut chips!... of parafin

I need a good way to control how the wax cools to prevent the creation of cavities in the middle of it I'm thinking just a cover so the top does not get a chance to solidify before the rest of it maybe.
@warpedmephisto: I am going to need it! I can use help what did you have in mind? I have a magnetic base with some loc-line links on it but I think I would rather have what you use so that it moves with the tool.